1. Field of the Invention
Aspects of the present invention relate to a method of searching for an optimum recording power of a recordable optical disc, and, more particularly, to a method of controlling a recording power of an optical disc apparatus, which is capable of reducing an optimum power control (OPC) performance time to search for an optimum recording power using a start power which is stored in a memory based on the optical disc manufacturer.
2. Description of the Related Art
With the development of technology for processing video and audio data, recording media for storing high definition video data and high quality audio data for a long time, for example, optical discs such as a series of DVDs including DVD-R/RW and DVD-RAM, are being researched and are available in the market. Also, as the need for storage capacity is reaching the limit of current media such as DVDs, new research is being focused on high density optical discs, for example, a Blu-ray disc recordable/rewritable (BD-R/RW) which is capable of recording data of a few Gigabytes.
In order to record data on such a high density optical disc, proper recording power should be defined. Recording quality and reproduction quality depend on the recording power, such that recording power can be defined as a standard. In order for the recording power to be at an optimum value, a relation between optical disc types and performance of optical disc apparatuses must be considered. However, since these relations cannot be uniformly determined, the optical disc apparatus must search for the optimum recording power and then record data to a corresponding optical disc in accordance with the determined optimum recording power, i.e., the best recording laser power setting for each optical disc and an optical disc apparatus combination. Therefore, the methods of searching for optimum recording power are standardized, and the standardized method is known as an optimum power control (OPC) process.
In order to perform OPC, a test zone is typically provided in a lead-in zone of an optical disc, such a test zone is used for determining an optimum recording power for recording data on the associated optical disc. When an optical disc apparatus performs an OPC in the test zone of an optical disc mounted therein and searches for the optimum recording power, the subsequent recording operation is performed using the determined optimum recording power.
However, since the recording power is dependent upon the state or type of an optical disc mounted on such an optical disc apparatus and the state of the optical disc apparatus (laser state, recording method, laser type, temperature characteristics, etc.), recording speed, and a modulation curve of the initial OPC starting power is different from that of the final power, a deviation of the optimum recording power, which is found through the OPC search operation, is significant. Also, when the recording operation is performed with the power determined after performing OPC, jitter characteristics deteriorate such that reproduction quality is decreased.
Also, since OPC determines the optimum recording power in an initial area which is characterized by the initial starting power rather than a saturation power, considering the characteristics of the modulation curve, it is important to set the initial starting power based on the current optical disc apparatus and the optical disc state in order to perform a stable OPC. However, the conventional method performs the OPC procedure to search for the optimum recording power without consideration of the above-mentioned factors and the OPC performing time requires at least 4 seconds, which affects lead-in time. Therefore, the performance of the total system is diminished.